Hitosuji Kyoushi is a very expensive private tutor. Best of all he likes to teach pretty young girls. He seduces them during his lessons and their parents don’t find that out at all. One day he goes to the home of Reiko Shirakawa. This shy girl is very silly and absolutely doesn’t understand math. So Hitosuji will show her how solve an equation of love.

A young girl Emi lives with her stepbrother Tomomi, who she falls in love with. One day an unknown woman comes to their house. She tells that she is a tax collector and the house will be sold to pay Emi’s father debts. Tomomi says Emi that he will try to find a way to pay debts off and leaves the house. Emi can’t imagine her life without her beloved stepbrother, so she comes to a dangerous journey to find him.

Keigo Nakadai enjoys life with his girlfriend Akemi, but suddenly got a mail from his cousine Misa. A while ago they were in love, but Misa went to another town to study and several time later they stopped sending letters to each over. Now she is going to return and Keigo will have to decide with whom of the two girls he wants to be.

Shinji Nakayama is a high school student who often cheats on his girlfriend Michiyo Sakagami. One day they have broken up because of it and now Shinji is being sad at home. Suddenly a strange girl falls on him out of nowhere. She tells Shinji that her name is Mako and she has come from the future to help him with his love problems. Shinji doesn’t understand what’s going on and a few time later another girl from the future comes to present time.

The protagonist is a high school student and at the same time a treasure hunter. He comes to a village to find a treasurse, hidden in a dungeons near that place. The problem is that he is not alone, other treasure hunters are trying to find the treasure first. At the same time a series of mysterious murders have happened in the village.

A college student Shinichi Kashiwagi has gone to a trip during his vacations. Suddenly a storm starts and Shinichi lose his consciousness and almost die. When he wakes up he finds out that he is in a big mansion where live a lot of people, most of whom are young girls. Nobody of them can leave this mansion, but the Mistress says Shinichi that if he helps girls solve their problems, the gates of the mansion may open and let him go with one more person.

In 2023 Hajime Kudo is enjoying downtime after his graduation from university. One day he gets an advertisment to a “May Club” a virtual dating service. In that club, after buying a ticket, you may sit in a chair of a VR machine and go to a virtual downtown. There you can find a lot of girls who are also using this service. Hajime can talk with them and go for a date and who knows, maybe, he find his true love there.

Amamiya private girl’s high-school is a very strange place. Last days several girls have disappeared there. Japanese Educational Society (JES) sent their agent to investigate those incidents. But she disappeared too. Now another agent of JES, Yuichi Sakuma comes to Amamiya school, pretending a new teacher of biology. Yuichi has to find out what is going on there and rescue his colleague and all disappeared schoolgirls.

Keigo Nakadai is no more a caretaker of “Paradise Heights”, but a designer in a toy-making company. He is living in “Paradise Heights” as one of the tenants. Most of the girls from the first game have moved out, but the others have taken their place. At the same time someone is stealing Keigo’s toy designs and Keigo has to find out who is it before it’s too late.

Keigo Nakadai quitted his job in a software developing company and started to work as a caretaker in “Paradise Heights” — apartments which belongs to his uncle. The apartment house is a very small building with only six flats (Keigo lives in one of them). All other people, living there, are young women, who are very pretty and, as Keigo realized soon, lustful. Soon Misa Nemoto, a daughter of the owner of “Paradise Heights” came there and decided to stay for a while. Perhaps she fell in love with Keigo.